Congress has the power to authorize the use of force. It can cut off funding or repeal its authorization of force if the objectives of the war have been achieved or if the president is derelict in prosecuting the war. But the Constitution does not authorize Congress to tell the president and his subordinate military commanders that land, sea, or air power is off the table. If a threat to national interests is serious enough, it is Congress’s job to authorize a war. It is then the president’s job to fight it, using whatever military assets are appropriate, in his judgment, to meet war’s unpredictable twists and turns.
I emphasize the president’s judgment because exercising it is precisely what being commander-in-chief entails. The president, a civilian, does not drive the tanks; but as commander, he does decide whether the tanks are necessary. In authorizing the use of force, Congress cannot require the president to deploy ground forces. Indeed, Congress is powerless to require the president to dispatch any forces whatsoever.
If Obama believes the risk of the nation’s being enmeshed in an “enduring” armed conflict (to borrow his proposed AUMF’s nonsense word) is more dangerous than the risks posed by attacking the enemy, he can refuse to fight at all. Or, as he has done in Iraq and is doing in Afghanistan, he can withdraw even as the enemy is on the rise — a command decision known, in less politically correct parlance, as surrender. But whatever command decisions the president makes, they are his decisions. He is politically accountable for them.